Comment 14 for bug 2039746

You didn't remove libcamhal-common.

Please show

$ systemctl status v4l2-relayd
$ cat /sys/class/video4linux/*/name
please check installed files of libcamhal-ipu6ep-common, and check if file exist to make sure you have everything installed correctly.
$ dpkg -L libcamhal-ipu6ep-common

Did you do the reboot after everything installed?